317L

Fasteners & Material Data

UNS S31703

What is 317L stainless steel and its applications?

317L stainless steel (UNS S31703) is a low-carbon austenitic grade containing more molybdenum than conventional 316L. It is used in chemical and other process equipment where additional resistance to general or localized corrosion is needed.

  • Chemical processing: Equipment handling compatible acidic and chloride-bearing fluids.
  • Pulp and paper plant: Process components selected against the actual chemical stream.
  • Process piping: Connections where corrosion assessment indicates an advantage over 316L.

Choose your 317L product

Engineering Application & Selection Guide

Additional molybdenum improves corrosion resistance in relevant environments; low carbon helps limit sensitization following welding. These features do not produce a heat-treatable high-strength fastener grade.

  • 317L hex bolts — For chemically exposed joints, record fluid concentration, temperature and cleaning cycles before confirming the material.
  • 317L stud bolts — For flange connections, specify nut compatibility and finished-part mechanical requirements alongside corrosion requirements.
  • 317L hex nuts — Define thread tolerance, required load capacity and installation practice with the mating bolt.

Use the 317L and 316L comparison to assess the extra molybdenum in context. If severe crevice corrosion is the concern, also examine higher-alloy options such as 254 SMO; a small composition increase is not proof of adequate service life.

317L Composition

Selected composition limits · wt.%

ElementWeight %
Cr
18–20%
Ni
11–15%
Mo
3–4%
C
≤0.03%

ASTM / ASME specifications by product form

Finished-product requirements

Specify the finished-fastener mechanical requirements, condition and inspection separately from the starting-stock specification.

317L hex bolt requirements ↗

Fasteners · dimensional references

ProductReference
Hex boltsISO 4014 / ISO 4017 · ASME B18.2.1
Threaded studsDIN 976-1 · ASME B18.31.2
Hex nutsISO 4032 · ASME B18.2.2
Socket head screwsISO 4762 · ASME B18.3
Flat washersISO 7089 / ISO 7090 · ASME B18.21.1
Custom fastenersCustomer drawing

Raw-material specifications

Product form / scopeReference
Plate, sheet & strip · Specify grade, condition and order requirements.ASTM A240 / ASME SA-240

Dimensions do not define material or finished-part compliance. Specify the grade, condition and applicable requirements.

How to specify round bar, plate, wire and strip ↗

317L Mechanical Properties

Reference sample and condition

Data basis
Minimums quoted by producer
Test sample form
Plate, sheet & strip
Condition
Annealed
Test temperature
Room temperature
Gauge length
2 in (51 mm)
Key propertiesValue
Tensile strength≥515 MPa
0.2% yield strength≥205 MPa
Elongation≥40%
ATI · 316 / 316L / 317 / 317L · Technical Data Sheet · ASTM A240 / ASME SA-240 minimum-properties table ↗

Procurement and application guide

Specify the material and final condition

Review chloride concentration, temperature and crevice conditions.

Material forms in the technical reference: Plate · Sheet · Strip.

Define the finished-part acceptance

Include the material or bolting specification, required final condition, dimensions and quantity. State the service medium, temperature and loading where known. Agree the required tests, inspection coverage and acceptance criteria for the finished part.

Start with the information you have

Send a drawing or share the product form and dimensions. Identify any undecided requirements for review rather than copying a typical property value into the purchase order.

Upload Drawing

Technical guides

All technical articles ↗

Quality documents

EN 10204 3.1 MTC

Material certification and heat-number traceability

Mechanical testing

Methods and acceptance criteria follow the agreed specification

Alloy 718 laboratory report · PDF ↗

Thread inspection

Sampled GO/NO-GO gauging for threaded products

Additional inspection and records

Heat-treatment records, PMI and third-party scope agreed per order

View PMI sample ↗

Specify your 317L fastener

Sources and references

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